请教条SQL语句

Question

现在有两个表
table1                                        table2
ID     line      product    price            ID     line      price 
1       1           a                         1       1        12.00
1       2           b                         1       2        12.00
2       1           c                         2       1        6.00
2       2           d                         2       2        7.00
3       1           a                         3       1        10.00
3       2           c                         3       2        9.00
3       3           f                         3       3        7.00
4       1           g其中ID和line能确定唯一行，现在怎么把table2的price，对应更新到talbe1的price字段？

Answer 1

 update table1 set price=b.price from table1 a,table2 b where a.id=b.id and a.line=b.line

Answer 2

update a 
set a.price = b.price 
from table1 a,table2 b 
where a.id = b.id and a.line = b.line